Dihodium catalysts have been employed as catalysts in a variety of chemical reactions. One of the major drawbacks of using dirhodium catalysts is the expense of rhodium metal. Typically, to overcome the costs associated with catalysts containing expensive metals, two approaches can be used: (i) increasing the efficiency (e.g., turnover number and/or turnover rate) of the catalyst and/or (ii) recovering the spent catalyst from the reaction mixture so that the expensive metal can be separated and recycled. Neither approach has had much success with chiral dirhodium catalysts.
The present invention is directed to methods for increasing the efficiency of dirhodium catalysts and to methods and compositions that are useful in carrying out dirhodium-catalyzed reactions.